Stencil printing machine



Aug. 15, 1933. R. B. ALDCROFTT STENCIL- PRINTING MACHINE Filed Jan. 2,1932 s Shets-Sheet 1 I 2111012 for RickardBflldcro/fi. M

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R. B. ALDCROFTT STENCIL PRINTING MACHINE Filed Jan. 2, 1932 Aug; 15,1933.

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STENCIL BRINTING MACHINE Filed Jan. 2, 1932 3 Sheets-Sheet 3 PatentedAug. 15, 1933 UNITED STATES PATENT; oFFIc My invention relates toprinting devices, referring especially to mechanically fed printingmachinery, and is directed to a novel construction particularlyadaptable to stencil printing.

The two essential working parts of atypical printing machine are aplaten to receive and support stock, and means cooperating with theplaten to print the stock. In a machine for the stencil process ofprinting, the printing means comprises a stencil in combination with asqueegee adapted to force paint through the stencil to the stock. Whileit is to be understood that my invention, as a whole, is applicable toany type of printing machinery, and, in part, may be adapted to othertypes of machinery for processing substantially flat pieces ofmaterial,I shall, for the purposes of this application, confine m'y disclosure toa specific type of stencil printing machine.

A prime object of my invention, as so embodied, is to carry out thestencil printing process at a relatively, high rate of production and,as one means to this end, I minimize the movement of these two essentialworking parts. the stencil and' the platen. These members are relativelylarge and heavy, especially the platen. By reducing their range ofmovement, I not only make possible an increased rate of operation, but Ialso I reduce power consumption and the stress and wear that necessarilyaccompany extensive movement of relatively heavy members. Extensivemovement either of the platen or the stencil is.

usually required because of the necessity of providing sufficientclearance for feeding stock to the platen by hand. I avoid the necessityfor such extensiveness of movement by introducing a mechanical feed orconveying means that requires relatively little clearance between theplaten and,

' manner with the platen to register stock for the printing operation.

Preferably, the conveying means comprises a plurality of spaced parallelbelts moving in a plane across the platen. The platen has stops orguides to arrest the movement of the stock in suitable registry with thestencil prior to the printing period, and means is 'provided to releasethe stock to the conveyor subsequent to the printing period.

My conveyor system incorporates several novel features. including theprinciple of moving rectangular stock in a disalined or oblique positionagainst guides in converging alinement on both sides of the leadingcorner of the stock. These features will best be explained in thedetailed description to follow, wherein other objects and advantages ofmy invention will also become apparent.

In the accompanying drawings-- Fig. 1 is a side elevation of the stencilprinting machine;

Fig. 2 is a fragmentary central longitudinal vertical section throughtheupper part of the machine;

Fig. 3 is a front end elevation of a portion of the machine;

Fig. 4 is a top plan view partly in section taken as indicated by theline 4-4 of Fig. 1;

Fig. 5 is a fragmentary horizontal section taken as indicated by theline 55 of Fig. 1;

Fig. 6 is an enlarged side elevation of a stop or guide;

Fig. 7 is an enlarged plan view of the same;

Fig. 8 is an enlarged plan view of a guide clip on a conveyor belt;

Fig. 9 is an enlarged section of the clip taken as indicated by the line9-9 of Fig. 8;

Fig. 10 is an enlarged vertical section through a latchincorporated inmy invention;

Fig. 11 is an enlarged plan view of the latch;

Fig. 12 is a fragmentary enlarged vertical section taken along the line12-12 of Fig. 4 to show one end of the platen and parts cooperatingtherewith;

Fig. 13 is a series of diagrammatic sketches indicating the functionalrelationship of the conveyor means to the platen in the preferred formor my invention;

Fig. 14 is a similar series of diagrammatic sketches to indicate thecorresponding relationship in a modified form of my invention; and

Fig. 15 is a graph or chart indicating the in the preferred 24, a pairof legs 25 at the front end, and a pair of diagonal braces 26 at therear end anchored to legs 23. The three legs are connected on each sideof the machine by longitudinal angle bar 2'7; and legs 23 and 24 areconnected on each side of the machine near their tops by angle bars 28and at the floor by angle bars 29. The two bars 29 are interconnected bya laterally positioned channel bar 29a. Legs 23 may be connectedtogether by transverse bar 30 and legs 24 similarly joined by bar 30a(Fig. 5)

As seen from above (Fig. 4), the rectangle defined by angle bars 20 isdivided into three panels, a feed panel 31 at the front end, a dischargepanel 32 at the rear end, and a central panel 00- cupied by the printingplaten generally designated 33.

Spaced above and overlapping both ends of platen 33 is a horizontalrectangular frame 37 of angle iron, which seats the wooden frame 38 ofstencil screen 39. Frame 37 is adjustably spaced from angle iron members20 by means of supporting screws 40, which screw-threadedly engagevertical bores in blocks 41 at each corner of frame 37, and have reducedlower ends 40a journalled in blocks 42 mounted on angles 20 and blocks43 mounted on legs 23 and 24. Screws 40 are diametrically bored at theirupper ends to receive pinsor other tools for adjusting the spacing offrame 37 relative to platen 33. Vertical bars 44 at each corner of frame3'? support a rail 45 on each side of the machine in parallel spacedrelation to frame 37. This rail 45 is a channel bar with its flangesdisposed inward to form an upper track 46 and a lower track 47, whichtracks cooperate with a squeegee generally designated 48.

The squeegees construction in functional relation to the tracks issubstantially that described and claimed in my copending jointapplication filed February 11th, 1929, Serially. Numbered 338,976,issued February 2d, 1932, as Patent Number 1,843,116, andentitledApparatus for producing screen printing, a spreader roller included inthe prior disclosure being omitted in the present structure.

The squeegees construction includes a transversely extending bar 51, tothe lower edge of which a scraper 52 is attached for engagement with thetop surface of stencil screen 39. Scraper 52 will preferably be formedof yielding material, such as rubber or the like. Pins secured to theopposite ends of, bar 51. carry rollers 53 positioned to ride upon track46 at each side of the machine. Likewise secured to the ends of bar 51are control rollers 54, which,'on each side of the machine, arepositioned to coact with track 4'7. Tracks 46 and 47 and rollers 53 and54 are so spacedthat the squeegee 48 is maintained in a forwardlyinclined position both during its forward and rearward movements, Track47 terminates short of each end of track 46 and terminates at its rearend in an upwardly turned tongue 55 and at its forward end in adownwardly turned tongue 56. On the forward movement of the squeegee,roller 54 engages the lower surface of track 47, and on the rearwardmovement of the squeegee, roller 54 engages the upper surface of track47, so that during the rearward movement scraper 52 moves in spacedrelation to the stencil screen.

Reciprocating movement of the squeegee is accomplished by means ,of apair of levers 57 piv- 'otally mounted at-their lower ends on studs 57acarried by bars 29 on both sides of the machine. Levers 57 are joined attheir upper ends by means of a transversely extending bar 58, to insureuniform and simultaneous movement. They are operatively connected withthe squeegee 48 by means of pins or studs 59, carried by the plate 51,the studs extending-between members 37 and 45 into longitudinallyextending slots 57b in the upper ends of levers 57. This form ofconnection permits swinging movement of the levers 57 to and from theposition indicated by dotted lines in Fig. 1.

Disposed across the surface of platen 33 longitudinally is a pluralityof belts or tapes, in this case four in number, 60, 61, 62 and 63. Atthe front end of the machine is a transverse roller 64, journalled inbearings 65 mounted on angle iron 21, and at the rear end of the machineis a similar roller 66 journalled in bearings 67 mounted on angle ironframe members 20. These two rollers carry the plurality of belts and arepositioned so that the belts are substantially horizontal against thesurface of platen 33 when the platen is at its lowermost position spacedfrom screen 39. A third transverse roller 68, journalled in bearings 69mounted on brace members 26, guides the returning belts under theplaten; and an idler roller 70, floatingly journalled in slots '71 ofstandards'72, depending from angles 20, serves to keep the belts taut aswell as to guide them and, furthermore, provides for a certain degree ofvertical flexibility of the belts, which, as will be apparent, isnecessary in the operation of my machine. To maintain the requiredspacing between the parallel belts, a guide plate '75 is mounted acrossthe two front legs 25. Four notches '76 are cut on the lower edge ofthis bar to guide, respectively. belts 60, 61, 62 and 63 (see Fig. 3).

Platen 33 has a metal base plate 77 carrying a layer or facing of wood78 (Fig. 12). The conveyor belts lie fiat against the facing '78 and areguided thereon by channels formed between five spaced cardboards 79mounted on the layer of wood 78. Cardboards '79 are slightly less thickthan the conveyor belts, so that a piece of printing stock laid flat onthe cardboarcls 79 across the conveyor belts wouldbe drawn across theplaten by longitudinal movement of the belts. It is desirable that thedifference in thickness between cardboards 79 and the conveyor belts bevery.

slight. however, in order that substantially uniform pressure .may, beexerted against the under side of the stock when the platen is movedagainst stencil screen 39.

A guide-stop 80 extends above the surface of the platen between belts 60and 61, and a similar guide-step 81 is positioned between belts 62 and63, the guiding edges of the guide-stops being in slightly obliquealinement relative to the disposition of the conveyor belts. A thirdguide-stop 82 is positioned outside of belt 63 in perpendicularalinement to the oblique alinement of guide-stops 80 and 81, as may beunderstood by reference to Fi 4.

The construction of these guide-stops is indi cated by Figs. 6 and '7.Each member consists of a light spring clip 83, the base portion ofwhichv has two parallel beveled slots 84 receiving screws 85, by meansof which the clip is secured to the upper surface of wood layer '78.Each clip is sprung upward from the base portion at an angle andterminates in a vertical portion 83a extending into apertures 87provided through wood layer 78 and plate '77. Normally, the clips extendabove the platen in the position shown in Fig. 6, but when the platenmoves against screen through apertures 87 to such an extent that theclips extend above the platen only the thickness of the piece of stockinterposed between the platen and the stencil screen.

To the under side of platen base plate '77, along the front and rearedges, respectively, are at-v tached transverse angles 88 by suitablescrews 88a, which angles may normally rest against the horizontalinwardly disposed flanges .89 of side platen, positioned to coact 'withthe vertical guides 94. One leg of each slide is attached to the outsideface of angle 88 by means of bolts 95', the other leg beingslidinglyseated in the complementary vertical slot 96 of thecorresponding guide 94. Guides 94 are metal blocks mounted within anglesof angle irons 20, the corners of the platen base plate 77 being notchedto clear the guides.

The platen is moved vertically by four vertical plungers 98, oneabutting the under surface of plate 77 near each corner, each plungerslidingly extending through a suitable aperture in flange 89 of angleirons 20, a guide collar 99 mounted to the under surface of flange 89,anda suitable aperture through angle iron 28.

Adjacent each end of platen 33 a plate 100 spans the two angle irons 20,being mounted on flanges 89 and having notches 101 at each end to avoidslides 93 and guides 94. At two intermediate points, each plate 100 hassuitable circular apertures 100a to slidingly'receive plungers 102 thatsupport a cross-bar 103. Preferably, short plates 104 are attached tothe under side of plate 100 at each aperture 100a in order to providematerial for extending the aperture axially,

.the better to maintain vertical alinement of the 109 oppose thepressure of springs 107. When the platen is displaced upward, cross-bars103 rise with it as if they were an integral part therewith. When'the'platen reaches its upper limit of vertical movement, a notch 111 ineach plunger 102 is engaged by a latch member 112 of a latch- Y ingmeans generally designated 113. The construction of this latching meansis indicated by Figs. and 1.1. Two small bracket pieces 114, attached toplate 100 by suitable screws 115, are placed back to back in spacedrelation and joined by apin 116 on which latch 112 is pivoted betweenthe two bracket pieces. The bracket pieces 114 define a smallcylindrical housing 11'! for a coiled e'xpansile spring 118, whichspring presses upward against a tongue 119. Tongue 119 is integral withlatch 112 and so positioned with reference to pin 116 that upwardpressure on tongue 119 tends to press latch 112 against plunger 102 intoengagement with notch 111.

It is apparent that when. a cross-bar' 103 is the dotted line at 135 inFig. 4. The operator, .in feeding the machine, places a blank piece oflifted sufficiently to effect engagement between I latch 112 and plunger102, the cross-bar will maintain its elevated position after the platendrops unless tongues 119 are depressed torelease latches 112 fromnotches 111. Such release, in timed sequence to the beginning of thedownward movement of the platen, is provided by a series of latchfingers 123, which are mounted on the front and rear edges of platenplate '77 in a similar manner as fingers 109. The free ends of latchfingers 123 are turned downward in vertical alinement with correspondingtongues 1 19. The latch fingers along the forward edge of the platen aredimensioned to trip the corresponding latches in advance of similaraction on the part of latch fingersalong the rear edge of the platenduring the course of the downward movement of the platen. Initially, asthe platen begins its downward movement, both cross-bars 103 remainstationary. During the course of the downward movement the cross-bar atthe forward edge of the platen drops into contact with fingers 109 andthen, in timed sequence to this movement, the cross-bar at the rearedge-of the platen drops against its corresponding fingers 109.

Mounted on angle bars to span feed panel 31 is a feed plate 125 havingits upper surface in contact with the under surfaces of the conveyorbelts. Near the forward edge of plate 125 are two guides, guide 126between belts and 61, and guide 127 between belts 62' and 63. These twoguides have their guiding edges presented towards the rear of themachine in transverse alinement of'somewhat greater obliqucness than thealinement of guide-stops and 81'previously described. In perpendicularalinement with guides 126 and'12'7 is a third guide 128. These guidesare of similar construction to clips 83, except that the free ends ofthe clips may rest upon plate 125, it not being necessary to provide forvertical retraction of the feed plate guides. These guides are adjustedfor a given piece of stock 130, to position the stock with onelongitudinal edge extending diagonally across belt 60, as shown in Fig.4.

At intervals on belt 60 are mounted guideclips 131, which areconstructed as shown in Figs. 8 and 9. The clip comprises two pieces, aspacing member 132 narrower than belt 60t and alined with the outer edgethereof, and a metal tongue 133 of substantially the same width 'as thebelt and flaring slightly upward towards its inner edge, rivets 134extending through the tongue, spacer and belt.

The conveyor belts traverse the machine across stock on the conveyorbelts and holds'the piece of stock lightlyagainst guides 126, 127 and128 in opposition to friction from the belt until contact is made withthe stock by a belt clip, as at 135. As soon as he feels the contact ofthe belt clip against the edge of the stock he releasesthe stock to theaction of the conveyor belts.

Thestock is carried along the belt in a position of greater obliquenessthan the alinement of stop guides 80 and 81 on platen 33. As a result,the leading edge of the stock makes contact first with stop-guide 81.Further movement of the conveyor belt after such contact causes thepiece of stock 130a (Fig. 4) to pivot on guide stop 81 until contact ismade with guide-stop 80. Guide-stops and 81 may be said to place thestock substantially in lateral alinement with the stencil, or, strictlyspeaking, with the stencil pattern, since the leading edge of the one isin alinement with the rearward edge of the other. At the instant theleading edge establishes contact with guide-stop 80 the piece of stock130a is spaced from guide-stop 82, but further movement of belt 60causes the belt clip to slide past the longitudinal edge of the stock,thereby exerting pressure to move the stock against guide-stop 82 to thefinal position shown in Fig. 4. Inefiect, the belt serves as a yieldingmeans to move the stock laterally, the belt being displaced as indicatedby the dotted lines at 136 (Fig. 4) when the clip passes over therearward corner of the stock. This action of the clip may be said toaline the stock longitudinally with the stencil, thereby completingregistration of the stock with the stencil. The principle of automaticregistration involved may be expressed as that of moving rectangularstock obliquely against guides in converging alinement corresponding toan obliquely alined stencil pattern, the stock being fed against theguides in alinement more oblique than the guides.

I find it desirable, for the purpose of providing sufficient pressure byclip 131 against the edge of the stock, to provide a guide against theoutside edge of belt GOintermediate rollers 64 and 66. This guide may beconveniently provided by mounting a small vertical bar 137 on the rearedge of frame 37. In Fig. 2, I showthe guide 137 mounted on a ,pin- 138to clear the adjacent cross-bar 103. Guide 137 is positioned adjacent tothe normal alinement of conveyor belt 60 and serves to shorten theproportion of the belt displaced in moving stock against guide 82. q

In the preferred form of my invention, the conveyor belts are incontinuous motion. Contact of a blank piece of stock with guide-stops80, 81 and 82 is effected while the platen is in its lowest position.After the stock is properly registered against the guide the platenmoves upward against the under side of stencil screen 39, depressing theguide-stops as the stock contacts the under surface of the stencilscreen.

The subsequent movement of the parts may be understood by reference tothe diagrammatic views in Fig. 13, beginning with position A showing theplaten against the stencil screen as just described. At position B theplaten has dropped slightly but not sufliciently to release the latchesassociated with either cross-bar. At position C the platen has droppedaway from the stencil screen a distance substantially greater than theextension of the guide-stop above the level of the platen. The forwardof the two cross-bars 103 drops suddenly and the piece of stock 1302)drops out of contact withstencil screen 39. The guidestops 80 and 81being below the plane of theconvcyor belts. no longer operate to preventmovement of stock on' the conveyor belts. When the stock has beencarried along sufficiently to'prevent interference with its progressupon return to normal relationship of the conveyor belts to theguide-stops, the second or rear cross-bar drops to position D,permitting the conveyor belts to drop, the guide-stops being thendirectly in the path of the oncoming new sheet of blank stock 1300.

. Actuation of the various moving parts above described. in proper timedsequence, is accomplished by mechanism in the understructure of themachine, including a main drive shaft 142 suitably journalled inbearings 143 mounted on angle bars 2'7 (Fig.5). This shaft may be drivenby any suitable means such as a motor (not shown).

At opposite ends of this shaft, outside the frame proper of the machine,are keyed two cam disks 144. On the inner faces of eachdisk is a'pair ofcontinuous flanges 145 which define an irregular eccentric cam groove146. The shape of this cam groove may be roughly described astriangular, approximately one-third of the cam groovebeing a concentricdwell at the outer edge of the disk as shown at 146a, the second thirdof the groove 146b moving inward, and a third section 1460 movingradially outward as the disks 144 are moved clockwise (Fig. 1). Engaginggroove 146 is a complementary follower or roller 147 mounted on theinner side of'the adjacent squeegee lever 57. It is apparent that as theshaft 142 is revolved clockwise, squeegee lever 57 will go through thefollowing cycle of movements: a period of rest at the rear edge of thestencil screen; a forward movement of the squeegee during substantiallyan equivalent interval of time; and a return movement of the squeegee inspaced relation to the stencil screen during a third period of time ofsubstantially equal duration.

At a central position, an irregular cam plate 148 is keyed to shaft 142.Generally described, this cam plate has an outer dwell 148d, anintermediate dwell 1482), and an inner dwell'l48c. The precise shape ofthe cam plate maybe ascertained from the chart shown in Fig. 15 to beconsidered below.

A roller 149, adapted to follow the periphery of cam plate 148, issuitably journalled in the bifurcate end of a follower arm 150, the twospaced ends 151 of the arm 150 engaging the opposite faces of disk 148as guides. Follower arm 150 is guided centrally by two spaced rollers152 mounted .between two channel iron standards 153, which in turn aremounted on frame member 29a. The opposite end of follower arm 150 ispivoted to a rocker arm 154 which is keyedto a rock shaft 155.

Rock'shaft 155 is suitably journalled in bearings 156 mounted on anglebar 27 and carries near each end in fixed angular relation to rocker arm154, two parallel rocker arms 160. The outer ends of rocker arms 160 areconnected by links 161 to the free ends of a pair of correspondinglevers 162, which pivotally depend from suitable studs 163 mounted onframe members 20.

The lower ends of the plungers 98 that elevate the platen, are eachpivotally connected to corresponding upper toggle links 164, which coactwith corresponding lower toggle links 165, the lower toggle links beingpivotally mounted at their lower ends to frame member 29. The rear pairof toggle links 165 are connected by a pair of horizontal spacedtransverse bars 166 and the front two toggle links 165 are similarlyconnected together by cross-bars 167. Toggle links 165 movesimultaneously by virtue of transverse bars 166, similar bars 167, andlongitudinal links 168. one of the links 168 on each side of the machineconnecting a front toggle link 165 to the corresponding rear toggle link165. Movement is transmitted to the system of toggle and interconnectinglinks just described by means of a link 169 on each side of the machineinterconnectin a rear toggle link 165 with the corresponding lever 162.

It is apparent that movements of follower arm 150 substantially radiallyinward and outwar from the center of rotation of cam plate 148 result incorresponding vertical movements of platen 33 by virtue of the togglesdescribed. The angular relation of cam plate 148 to cam groove 146 isgenerally indicated in Fig. 1, and may be precisely ascertained from thechart in Fig. 15.

Keyed to shaft 142 is a pulley 172, which drives rollers 66 and 68 bymeans of a drive belt 173, the belt crossing as shown between roller 68and drive pulley 1'72. The diameter of drive pulley 172 relative to thedriven conveyor rollers, and the total length of the conveyor belts 60,61,. 62

and 63 are such that the conveyor belts move onethird their total lengthwhen drive shaft 142 makes one complete revolution,and three belt clips131 are equally spaced on belt 60 in order that a new piece of blankstock may be fed to the platen during each cycleof movements occasionedby one revolution of the' drive shaft.

Fig. 15 is a graph of one of such cycles of movements. The degrees ofangular movement of the drive shaft are indicated at the top of thechart and the inches of belt traverse are indicated at the bottom. It isassumed that the belts travel 76 inches per revolution of drive shaft142. Vertical distances represent the relative vertical movements of thevarious moving parts involved. The platen moves up while the squeegee isidle adjacent the rear edge of the stencil screen 39. When the platenreaches its uppermost level, corresponding to the point M in Fig. 15,the parts of the machine are in the position indicated by Fig. 1,follower 149 having just entered outer dwell 148a of cam plate 148. Theplaten is maintained in contact with the stencil screen for'a limitedperiod. as indicated between the points M and N of Fig. 15, during whichtime squeegee 48 moves forward with scraper blade 52 in contact withstencil screen 39 and forces paint through the stencil onto the stock.'At point P, the squeegee having passed beyond the open pattern on thestencihthe platen begins to drop to the position corresponding tointermediate dwell 148b.

At pointP the guide-stops 80 and 81' have dropped out of range of theplurality of conveyor belts. At point Q the first or forward cross-bar103 drops and the printed stock drops from the under surface of thestencil to the conveyor belts to move towards discharge panel 32 (seeposition C of Fig. 13). The platen soon starts to drop slowly towards aposition corresponding to lower dwell 1480. and, after a sufficientperiod of time to permit the escape of printed stock past guidestops 80and 81, the second cross-bar 103 drops as indicated at point R. Thebelts then drop into the channels on the top surface of the platendefined by the spaced rectangular cardboards 79, and the guide stops 80,81 and 82, associated with the platen, are again extended through theplane of the conveyor belts, thereby being in a position to register thenext piece of blank stock, which registration is begun at the point S.Complete registration is accomplished at approximately point T. In themeantime, the squeegee has completed its return movement in spacedrelation to the stencil screen and has come to rest near the rear edgeof the screen for a period before the cycle is'completed.

The portion of the cycle following on point T represents a margin oftime sufficient to allow for belt slippage or belt creepage changing therelation in time of movement of clips 131 relative to other movements ofthe cycle. It is apparent that point T may shift to the 76" pointwithout causing trouble or delay. In practice,'longitudinal adjustmentof belt 60 is required at so infrequent intervals, and is so easilyaccomplished, that it is not found necessary to substitute sprocketdrives forbelt drives.

The machine may be constructed to function effectively with the frontcross-bar 103 omitted.

The action of such a construction may be understood by reference to Fig.14. Position A corresponds to position A of Fig. 13 above; the positionC corresponds with position C; and position D" corresponds with positionD. At position D' a piece of printed stock 130d is moving away, and apiece of blank stock 130e is moving towards the platen. An importantdifference between the two actions is that in the case of the secondconstruction the conveying belts drop away from the stencil screen at arelatively gradual rate, whereas in the first construction the beltsdrop away suddenly. I find that the employment of two cross-bars ispreferable because the sudden drop of the belt seems to reduce thelikelihood of a piece of printed stock clinging to the stencil sheet:

Mechanical elements may be incorporated in either or both forms of myinvention as means to overcome such tendency. For instance, in Fig. 14are indicated light leaf springs 175 mounted on the bottom surface ofthe stencil screen. The stock moves the springs against the stencil asindicated at position A, and when, subsequently, support is removed fromunder the stock, the springs tend to separate the stock from the stencilsheet as indicated at C.

Fig. 15 reveals the detailed characteristics of the preferred cycle ofmovements, but it is'not to be regarded as in any way limiting mydisclosure to this particular cycle. This detailed description of mypreferred embodiment of the invention, which is given for the purposesof complete disclosure and illustration of the principles involved,suggests a wide range of structural modifications and changes that maybe made without departing from the spirit of my invention. I reserve theright to all such modifications and changes that properly come withinthe scope of my claims below.

Having described my invention, I claim:

1. An apparatus .of the class described, having in combination: a frame;a stencil supported by the frame; a platen supported by the frame inspaced relation to the stencil, said stencil and platen being movablerelative to each other; means to bring the stencil and platen togetherfor a limited period; a squeegee movably associated with thestencil;means to move the squeegee across the surface of the stencil during saidperiod; conveyor means continuously traversing the platen to carry stockacross the platen; guides on the platen to stop and position stock inproper registry with the stencil prior to said period;

and means to release the stock to the conveyor subsequent to saidperiod.

2. An apparatus of the class described, having in combination: a frame;a stencil supported by the frame; a platen supported by the frame inspaced relation to the stencil, said stencil and platen being movablerelative to each other; means to bring the stencil and platen togetherfor a limited period; a squeegee movably associated with the stencil;means to move the squee-. gee across the surface of the stencil duringsaid period; horizontal conveyor means continuously traversing theplaten to carry stock across the platen; guides on the platen to stopand position stock in proper registry with the stencil prior to saidperiod; and means to provide vertical displacement of the conveyorrelative to the guides to clear the guides subsequent to said period.

3. An apparatus of the class described, having in combination: a frame;a stencil supported by the frame; a platen supported by the frame inspaced relation to the stencil, said stencil and platen being movablerelative to each other; means to bring the stencil and platen togetherfor a limited period; a squeegee movably associated with the stencil;means to move the squee gee across the surface of the stencil duringsaid i period; horizontal conveyor means continuously traversing theplaten to carry stock across the platen; guides on the platen positionedto stop stock in proper registry with the stencil, said conveyor meansand guides being vertically movable relative to each other; and means toprovide said vertical movement in timed sequence to said period wherebystock is stopped onthe conveyor prior to said period and releasedsubsequent to said period.

4. An apparatus of the class described, having in combination: a frame;a horizontal stencil member supported by the frame; a platen membersupported by the frame under the stencil in spaced parallel relationthereto; one of said members being vertically movable against the othermember; means to move the one member against the other member for a,limited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;conveyor means to carry stock across the platen longitudinally; guidemeans associated with the platen to delay the longitudinal movement ofthe stock at substantially lateral alinement with the stencil duringsaid period; a guide associated with the platen to abut stock'atlongitudinal alinement with the stencil;'and means associated with theconveyor to shift the stock against said guide, thereby properlyregistering the stock with the stencil prior to said period.

5. An apparatus of the class described, having in combination: a frame;a horizontal stencil supported by the frame; a vertically movable platensupported by the frame under the stencil in parallel spaced relationthereto; means to move the platen upw'ard against the stencil for alimited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;continuously operating conveyor means to carry stock across the platen,said means being adapted to be displaced upward with the platen; guidesextending upward from the platen to engage stock on the conveyor inproper registry with the stencil during said period; and means to delaythe lowering of the conveyor means after said period, thereby releasingstock from the guides to the conveyor 6. An apparatus of the classdescribed, having in combination: a frame; a stencil supported by theframe; a platen supported by the frame in spaced relation to thestencil, said stencil and platen being movable relative to each other;means to bring the stencil and platen together for a limited period; asqueegee movably associated with the stencil; means to move the squeegeeacross the surface of the stencil during said period; a continuousflexible stock-carrying ,conveyor means continuously traversing theplaten in one direction; and means associated with the platencooperative with the conveyor means to halt stock on the platen duringsaid period,

7. An apparatus of the class described, having in combination: a frame;a horizontal stencil supported by the frame; a vertically movable platensupported by the frame under the stencil in parallel spaced relationthereto; means to move the platen upward against the stencil for alimited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;a continuous flexible stock-carrying conveyor means continuouslytraversing the platen longitudinally; guides on the platen to stop andposition stock in proper registry with the stencil prior to said period;and means to provide vertical displacement of the conveyor relative tothe guides to clear the guides subsequent to said period.

8. An apparatus of the class described, having in combination: a frame;a horizontal stencil supported by the frame; a vertically movable platensupported by the frame under the stencil in parallel spaced relationthereto; means to move the platen upward against 'the stencil for alimited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;a continuous fiexible' stock-carrying conveyor means continuouslytraversing the platen longitudinally; guide meansassociated with theplaten to stop the longitudinal movement of stock at substantiallylateral alinement with the stencil prior to said period; a guideassociated with the platen to abut stock at longitudinal alinement withthe stencil; means associated with the conveyor to shift the stockagainst said guide, thereby properly registering the stock with thestencil prior to said period; and means to flex the conveyor means outof range of said guide means subsequent to said period.

- 9. An apparatus of the class described, having in combination: aframe; a horizontal stencil supported by the frame; a vertically movableplaten supported by the frame under the stencil in parallel spacedrelation thereto; means to move the platen upward against the stencilfor a limited period; a squeegee movably associated with the stencil;means to move the squeegee across the surface of the stencil during saidperiod: a continuous flexible stock-carrying conveyor means continuouslytraversing the platen longitudinally, 1

and adapted to be flexed upward by the upward e movement of the platen;guide means associated with the platen to stop the longitudinal movementof stock at substantially lateral alinement with the stencil prior tosaid period; a guide associated with.the platen to abut stockatlongitudinal alinement with the stencil; means associated with theconveyor means to shift the stock against said guide, thereby properlyregistering the stock withthe stencil prior to said period; and means tomaintain the conveyor means in the flexed position for a short intervalafter the platen is lowered, thereby providing for release of stock fromthe guide means.

10. Anapparatus'of the, class described, having in combination: a frame;a horizontal stencil supported by the frame; a vertically movable platensupported by the frame 'under the stencil in parallel spaced relationthereto; means to move the platen upward against the stencil for alimited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;a continuous flexible stock-carrying conveyor means continuouslytraversing the platen longitudinally; guides on theplaten to stop andposito said period; a cross-member associated with the platen andmovable through substantially the same vertical range, the conveyormeans being adapted to be flexed upward by the upward move ment of theplaten and cross-member; means associated with the platen to move thecrossmember upward therewith; a latch to releasably hold thecross-member at its upper position; means to trip the latch after aninterval from the time the platen lowers sufficiently to carry saidguides out of engagement with the "stock; and yielding means to lowerthe cross-member.

ll. An apparatus of the class described, having in combination: a frame;a horizontal stencil supported by the frame; a vertically movable platensupported by the frame under the stencil in parallel spaced relationthereto; means to move the platen upward against the stencil for alimited period; a squeegee movably associated with the stencil; means tomove the squeegee across the surface of the stencil during said period;a continuous flexible stock-carrying conveyor means continuouslytraversing the platen longitudinally; guides on the platen to stop andposition stock in proper registry with the stencil prior to said period;a cross-member associated with the front edge of they platen and movablethrough substantially the same vertical range; a second and similarcross-member associated with the rear edge of the platen, the conveyormeans being adapted to be moved upward by upward movement of the platenand the two trip the first latch when the platen lowers sufliciently tocarry the guides out of engagement with the printed stock; and means totrip the second latch .after the printed stock is carried substanatially clear of the guide means.

'12. An apparatus of the'class described, having in combination: aframe; a horizontal stencil supported by the frame; a vertically movableplaten supported bythe frame under the stencil in parallel spacedrelation thereto; means to move the platen upward against the stencilfor a limited period; a squeegee movably associated with the stencil;means to move the squeegee across the surface of the stencil during saidperiod; a continuous flexible stock-carrying conveyor means continuouslytraversing the planten longitudinally; a cross-member associated withthe platen and movable through substantially the same vertical range,the conveyor means being adapted to be flexed upward by the upwardmovement of the platen and cross-member; guide means associated with theplaten to stock the longitudinal movement of stock at substantiallylateral alinement 'with the stencil prior to said period; a guideassociated with the platen to abut stock at longitudinal alinement withthe stencil; means associated with the conveyor to shift the stockagainst said guide, thereby properly registering the stock with thestencil priorto said period; means associated with the platen to movethe cross-member upward therewith; a'latch to releasably hold thecross-member at its upper position; means to trip the latch after aninterval from the time the platen lowers sufficiently to carry saidguides out of engagement with the stock; and yielding meansto lower thecrossmember.

13. An apparatus of the class described, having in combination: a frame;a stencil sppported by the frame, said stencil having a printing patternpositioned oblique to the alinement of, the frame; a platen supported bythe frame in spaced relation to the stencil, said stencil and platenbeingmovable relative to each other; means to bring the stencilandplaten together for a limited pe-' riod; a squeegee movably associatedwith the stencil; means to move the squeegee across the surface of thestencil during said period; ,a conveyor to carry stock to the platenprior to said period and to remove stock therefrom subsequent to saidperiod; and guides adapted to cooperate with the conveyor to registerthe stock with the stencil pattern, said'guides being in convergingalinement corresponding to the oblique position period; a squeegeemovably associated with the stencil; means to move the squeegee acrossthe surface of the stencil during said'period; conveyor meanscontinuously traversing the platen to carry stock across the platen; andguides on the platen to stop' and positionstock in proper registry withthe stencil prior to said period, said guides being in convergingalinement corresponding to the oblique position of the stencil pattern.

15. An apparatus of the class described, having in combination: a frame;a stencil supported bythejrame, said stencil having a printing patternpositioned oblique to the alinement of the frame; a platen supported bythe frame in spaced relation to the stencil, said stencil and platenbeing movable relative to each other; means to bring the stencil andplaten together for a limited period; a squeegee movably associated withthe stencil; means to move the squeegee across the surface of thestencil during said period; horizontal conveyor means continuouslytraversing the platen to carry stock across the platen; guides on theplaten positioned to stop stock in proper register with the stencil,said conveyor means and guides being vertically movable relative to eachother; said guides being in converging alinement corresponding to theoblique position of the stencil pattern; and means to provide saidvertical movement in timed sequenceto said period whereby-stock isstopped on the conveyor prior to said period and released subsequent tosaid period.

16. An apparatus of the class'described, having in combination; a frame;a stencil supported by the frame; said stencil having a printing patternpositioned oblique to the alinement of the stencil; means to move thesqueegee across the surface of the stencil during said period; conveyormeans continuously traversing the platen to carry stock across theplaten; guides on the platen to stop and position stock in properregistry with the stencil prior tosaid period, said guides being inconverging alinement corresponding to the oblique position of thestencil pattern and feed guides to position blank stock on the conveyorat greater obliqueness than the alinement of the platen guides.

17. An apparatus of the class described, having in combination: a frame;a stencil supported by the frame, said stencil having a printing patternpositioned oblique to the alinement of the frame; a platen supported bythe frame in spaced relation to the stencil, said stencil and platenbeing movable relative to each other; means to bring the stencil andplaten together for a limited period; a squeegee movably associated withthe stencil; means to move the squeegee across the surface of thestencil during said period; horizontal conveyor means continuouslytraversing the platen to carry stock across the platen; guides, on theplaten positioned to stop stock in proper registry with the stencil,said conveyor means and guides being vertically movable relative to eachother, said guides being in converging alinement corresponding to theoblique position of the stencil pattern; means to provide said verticalmovement in timed sequence to said period whereby stock is stopped onthe conveyor prior to said period and released subsequent to saidperiod: and feed guides to position blank stock on the conveyor atgreater obliqueness than the alinement of the platen guides.

18. An apparatus of the class described, having in combination: a frame;a horizontal stencil supported by the frame, said stencil having aprinting pattern positioned oblique to the alinement of the frame; avertically movable platen supported by the frame under the stencil inparallel spaced relation thereto; means to move the platen upwardagainst the stencil for a limited period; a squeegee movably associatedwith the stencil; means to move the squeegee across the surface of thestencil during said period; continuously operating conveyor means tocarry stock across the platen, said means being adapted to bedisplaced'upward with the platen; guides extending upward from theplaten to engage stock on the conveyor in proper registry with thestencil during said period, said guides being in converging alinementcorresponding to the oblique position of the stencil pattern; means to astock conveyor traversing the machine; guides on the machine associatedwith the conveyor to position the stock for a limited period ofprocessing, said guides being in oblique alinement converging on thepath of the conveyor; and feed guides onthe machine associated with theconveyor to position stock on the conveyor at, greater obliqueness thanthe alinement of the first named guides.

20. The combination with a machine to process rectangular stock, offeeding means comprising: a stock conveyor continuously traversing themachine; guides on the machine associated with the conveyor to stop andposition the stock for a limited processing period; said guides being inoblique alinement converging on the path of the conveyor; and feedguides on the machine associated with the conveyor to position stock onthe conveyor at greater obliqueness than the alinement of the firstnamed guides.

' 21. The combination with a machine to process rectangular stock, offeeding means comprising: a stock-conveyor continuously traversing themachine; a guide on the machine associated with the conveyor to abut theleading edge of the stock for a limited period in suitable lateralalinement for processing; a guide on the machine to abut a side edge ofthe stock in suitable longitudinal alinement for processing, said guidesbeing in oblique alinement converging on the path of the conveyor; andfeed guides on the machine associated with the conveyor to positionstock on the conveyor at greater obliqueness than the alinement of thetwo first named guides.

22. The combination with a machine to process rectangular stock, offeeding means comprising: a stock-conveyor traversing a work-portion ofthe machine; and guides on the machine adapted in opposition to theconveyor to temporarily stop the stock in a position for processing,said guides being in oblique alinement converging on the path of theconveyor.

23. The combination with a machine incorporating means to processrectangular stock, of feeding means comprising: a stock-conveyortraversing a work-portion of the machine; guides on the machine adaptedin opposition to the conveyor to stop the stock in a processing positionoblique to the direction of travel of the conveyor, said guidesconverging on the p th of the conveyor, said conveyor and said gu desbeing-movable relative to each other in a direction perpendicular to theplane of the conveyor, and means synchronized with the processing meansto provide such relative movement between the conveyor and the guides.

RICHARD B. ALDCROF'I'T.

